Mark task-9 (Listmonk newsletter) as Done

All acceptance criteria confirmed — double opt-in email received,
Katheryn set as notify email for new subscribers.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backlog/tasks/task-9 - Set-up-Listmonk-newsletter-with-Mailcow-SMTP.md

@@ -1,7 +1,7 @@
 ---
 id: task-9
 title: Set up Listmonk newsletter with Mailcow SMTP
-status: In Progress
+status: Done
 assignee: []
 created_date: '2026-02-03 08:16'
 labels:
@@ -30,7 +30,7 @@ Requirements:
 - [x] #1 Listmonk deployed and accessible via web UI
 - [x] #2 Mailcow SMTP configured and sending test emails
 - [x] #3 Subscribe form on katheryn site connected to Listmonk
-- [ ] #4 End-to-end test: subscribe and receive newsletter
+- [x] #4 End-to-end test: subscribe and receive newsletter
 <!-- AC:END -->
 
 ## Notes
@@ -44,4 +44,5 @@ Requirements:
 - API user `api-frontend` with token auth for frontend integration
 - Frontend subscribe route updated to call Listmonk API (token auth)
 - Fallback to email notifications when Listmonk env vars not set (local dev)
-- AC #4 pending: needs frontend rebuild+deploy, then real email test
+- Switched to public subscription API (/api/public/subscription) — no auth needed, triggers opt-in automatically
+- AC #4 confirmed: subscribe via staging → opt-in email received at jeffemmett@gmail.com